This application claims the benefit of Korean Application No. P2002-78377 filed in Korea on Dec. 10, 2002, which is hereby incorporated by reference in its entirety.
1. Field of the Invention
The present invention relates to a liquid crystal display panel, and more particularly to a liquid crystal display panel that is adapted to preventing static electricity from coming into picture display part and a fabricating method thereof.
2. Description of the Related Art
Generally, a liquid crystal display uses an electric field across a liquid crystal having dielectric anisotropy to control the light transmittance of the liquid crystal. A liquid crystal display panel includes a plurality of liquid crystal cells in a matrix that each contain liquid crystal and a transistor. The matrix of liquid crystal cells is controlled using a driver circuits so that a picture is displayed on the liquid crystal display panel.
More particularly, the liquid crystal display panel is provided with gate lines in one direction and data lines in other direction such that the gate lines and data lines cross over each other. Each liquid crystal cell is adjacent to a crossover of a gate line and a data line. A common electrode is provided in all of the liquid crystal cells of the liquid crystal display panel. A pixel electrode is provided in each of the liquid crystal cells. A Thin Film Transistor (xe2x80x9cTFTxe2x80x9d) is also provided in each of the liquid crystal cells. Each of the pixel electrodes is connected to a data line through a source electrode and a drain electrode of a TFT. Accordingly, the TFTs of a display part of a liquid crystal display panel are used as switching devices for apply electric fields to the liquid crystal in the liquid crystal cells from the data lines. Each of the gate electrodes of the TFTs is connected to a gate line, which allows pixel voltage signals from the data lines to be applied to the pixel electrodes in response to scan signals from the gate lines.
The driver circuits include a gate driver for driving the gate lines and a data driver for driving the data lines. The gate driver sequentially applies scan signals to the gate lines to sequentially drive the liquid crystal cells of the liquid crystal display panel. The data driver applies video signals to each data line whenever the gate signal is applied to any one of the gate lines. Accordingly, the light transmittance is controlled by way of the electric field applied between the pixel electrodes and the common electrode in accordance with the video signal, thereby displaying a picture on all of the liquid crystal cells of a liquid crystal display panel.
The TFT of a liquid crystal display panel can use an active semiconductor layer formed of amorphous silicon or polycrystalline silicon. An amorphous type liquid crystal display panel that uses TFTs with an amorphous silicon active layer has the advantages of all the TFTs across a matrix of liquid crystal cells having relatively the same electrical characteristics and being relatively stable in their electrical responsiveness. However, the low carrier mobility of the TFTs in an amorphous type liquid crystal display panel makes it difficult to improve pixel density. In the alternative, the poly-type liquid crystal display panel that uses TFTs with a polycrystalline silicon active layer has the advantage of higher pixel density because the polycrystalline silicon active layer has a high carrier mobility. Further, fabricating costs can be reduced because the driver circuits can be mounted on the same substrate as the liquid crystal display panel.
FIG. 1 is a plan view illustrating a configuration of a poly-type liquid crystal display in the related art. As shown in FIG. 1, a liquid crystal display device includes a liquid crystal display panel 10 with a gate driver 12 for driving gate lines GL1 to GLn of the liquid crystal display panel 10 and a data driver 14 for driving data lines DL1 to DLm of the liquid crystal display panel 10. The gate driver 12 sequentially drives the gate lines GL1 to GLn with gate control signals in horizontal periods for each frame of a video signal. The gate driver 12 turns on the TFTs in a horizontal line, so as to allow the data lines DL1 to DLm to be connected to a horizontal row of liquid crystal cells.
The data driver 14 of the liquid crystal display device in FIG. 1 takes samples of a plurality of digital data signals and converts the sampled signals into analog data signals for each horizontal period. The data driver 14 applies the analog data signals to the data lines DL1 to DLm. Accordingly, the liquid crystal cells connected to the turned-on TFTs control the light transmittance in response to the data signals from the data lines DL1 to DLm, respectively.
The liquid crystal display device of FIG. 1 also includes multiplexers MUX1 to MUXk connected between the data driver 14 and the data lines DL1 to DLm. Each multiplexer MUX1 to MUXk is connected to a plurality of data lines, such as the three data lines DLi to DLi+2. Each multiplexer MUX1 to MUXk sequentially applies the video signals, which are supplied from the data driver 14 through a data input line DILi, to three data lines DLi to DLi+2 in accordance with a first to a third control signal supplied through a first to a third control line CL1 to CL3. To this end, each multiplexer MUX1 to MUXk includes three switching devices SW1 to SW3 each connected between a data input line DILi connected to the data driver 14 and respective one of three data lines DLi to DLi+2. Each switching device SW1 to SW3 is normally implemented as an MOS transistor. Each of three switching devices SW1 to SW3 included in the multiplexer MUX receives the first to third control signals at each gate electrode of the switching devices SWi. The first to third control signals have an enable interval, where the control signals progress sequentially to each other and repeatedly, such as an interval of high logic. Accordingly, three switching devices SW1 to SW3 included in the multiplexer are sequentially turned on for each horizontal period to allow the three data lines DLi to DLi+2 to be connected to the data input line DILi, which is connected to the data driver 14. The multiplexers MUX1 to MUXk are formed within the liquid crystal display panel 10 together with a picture display part 16. Typically, the multiplexers MUX1 to MUXk are located adjacent to the picture display part 16 of the liquid crystal display panel 10.
The picture display part 16 has groups of red R, green G and blue B pixels. Each of the red R, green G and blue B pixels consists of a liquid crystal cell with a thin film transistor and liquid crystal. A color filter provided in liquid crystal cell of either red, green and blue respectively defines a red R, green G and blue B pixel.
A fabricating process of such a liquid crystal display panel is divided into a substrate patterning process, an alignment film forming process and a substrate bonding/liquid crystal injection process. The substrate patterning process is subdivided into a patterning process of an upper substrate and a patterning process of a lower substrate. The upper substrate is provided with a black matrix, a color filter and a common electrode. The lower substrate is provided with signal lines, such as the data lines and gate lines, and TFTs for the liquid crystal cells. Subsequently, pixel electrodes are provided for each of the pixel cells. In addition, a plurality of multiplexers for driving the data lines on a basis of time-division is also formed on the lower substrate. Subsequently, an alignment film is formed on either or both the common electrode and the pixel electrodes.
In the substrate bonding/liquid crystal injection process, a sealant is applied to one of the upper and lower substrate. The upper and lower substrates are then bonded together while leaving a hole for injection of liquid crystal between the upper and lower substrates. After the liquid crystal is injected in between the upper and lower substrates, the hole in the sealant is sealed.
Lastly, in a test process, the operating state of the drivers that drive the gate lines and the data lines is tested and bad pixels are detected. FIG. 2 is a view illustrating a shorting-bar for use in testing and draining away static electricity that otherwise would come into the poly-type liquid crystal display panel shown in FIG. 1. As shown in FIG. 2, a shorting bar 20 is used for such test processes to prevent the build up of static electricity. The shorting bar 20 is connected to a ground voltage source GND during the fabricating process and drains away the static electricity transmitted to the gate lines and data lines of the liquid crystal display panel to protect the TFTs in the display part 16 from static electricity.
FIG. 3 is a sectional view of a poly-type liquid crystal display panel, taken along a scribed line SCL1 shown in FIG. 2. As shown in FIG. 3, the shorting bar 20 is formed of the same material as the data input line DILi on an interlayer insulating film 30 above at an edge end part of the lower substrate in a non-display part. Further, the shorting bar 20 is formed crossing over the control lines 22, which are formed on a gate insulating film 28, with the interlayer insulating film 30 therebetween. As shown in FIG. 3, the protective layer 32 formed above the shorting bar 20, which is formed over the control lines 22 has a mesa profile with respect to the rest of the protective layer 32.
After completion of the test process, the scribed line SCL1 is formed with a scribing process of the lower substrate 24. At this moment, the scribed line SCL1 is formed to go over the shorting bar 20 in a perpendicular direction to the control lines 22. Typically, in the related art liquid crystal display panel, there occurs a short-circuit between the control lines 22 and the shorting bar 20 formed above the control lines 22 on the interlayer insulating film 30 during the scribing process. Due to this short-circuit, there occurs a problem in that the static electricity will go into the inside of the liquid crystal display panel along the shorting bar 20 and the control lines 22.
Accordingly, it is an object of the present invention to provide a liquid crystal display panel that is adapted to preventing static electricity from coming into a picture display part of a liquid crystal display panel and a fabricating method thereof.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a liquid crystal display panel according to an aspect of the present invention including a display part having pixels; a non-display part having driving circuits for driving the display part; a control line formed in the non-display part for applying a drive signal to signal lines of the display part; a scribed line formed in an area of the non-display part crossing the control line; and a shorting bar that runs along the scribed line and bypasses around an area in which the scribed line crosses the control line.
A fabricating method of a liquid crystal display panel according to another aspect of the present invention includes forming a control line in a non-display part for applying a drive signals to signal lines of a display part; forming a shorting bar to bypass around an area; and forming the scribed line along the shorting bar and in the area of the non-display part, wherein the scribed line crosses the control line in the area.